The founder of the Wahhabi movement, Muhammed Ibn Abdul Wahhab (d. 1206H) in his book
كتاب مختصر الإنصاف والشرح الكبير, states:
https://al-maktaba.org/book/1685/155
In the above paragraph, he attests that the tarawih prayer is 20 rakahs (and 36 according to Imam Malik).
There is no mention of 8 rakahs of tarawih prayer being a valid position for obvious reason that such a position was never heard off. Its emergence was only recent and one of several innovated practices instituted by the pseudo salafis.
Wahhabism Unveiled 